Techniques for Power and Reliability Optimization of Cmos Logic


Book Description

As the transistors became smaller in size and the systems became faster, issues like power consumption, signal integrity, soft error tolerance, and testing became serious challenges. There is an increasing demand to put CAD tools in the design flow to address these issues at every step of the design process. First part of this research investigates circuit level techniques to reduce power consumption in digital systems. In second part, improving soft error tolerance of digital systems is considered as a trade off problem between power and reliability and a power aware dynamic soft error tolerance control strategy is developed. The objective of this research is to provide CAD tools and circuit design techniques to optimize power consumption and to increase soft error tolerance of digital circuits. Multiple supply and threshold voltages are used to reduce power consumption. Variable supply and threshold voltages are used together with variable capacitances to develop a dynamic soft error tolerance control scheme.




Hierarchical Optimization of Digital CMOS Circuits for Power, Performance and Reliability


Book Description

Power consumption and soft-error tolerance have become major constraints in the design of DSM CMOS circuits. With continued technology scaling, the impact of these parameters is expected to gain in significance. Furthermore, the design complexity continues to increase rapidly due to the tremendous increase in number of components (gates/transistors) on an IC every technology generation. This research describes an efficient and general CAD framework for the optimization of critical circuit characteristics such as power consumption and soft-error tolerance under delay constraints with supply/threshold voltages and/or gate sizes as variables. A general technique called Delay-Assignment-Variation (DAV) based optimization was formulated for the delay-constrained optimization of directed acyclic graphs. Exact mathematical conditions on the supply and threshold voltages of circuit modules were developed that lead to minimum overall dynamic and static power consumption of the circuit under delay constraints. A DAV search based method was used to obtain the optimal supply and threshold voltages that minimized power consumption. To handle the complexity of design of reliable, low-power circuits at the gate level, a hierarchical application of DAV based optimization was explored. The effectiveness of the hierarchical approach in reducing circuit power and unreliability, while being highly efficient is demonstrated. The usage of the technique for improving upon already optimized designs is described. An accurate and efficient model for analyzing the soft-error tolerance of CMOS circuits is also developed.




Low-Power CMOS Circuits


Book Description

The power consumption of microprocessors is one of the most important challenges of high-performance chips and portable devices. In chapters drawn from Piguet's recently published Low-Power Electronics Design, Low-Power CMOS Circuits: Technology, Logic Design, and CAD Tools addresses the design of low-power circuitry in deep submicron technologies. It provides a focused reference for specialists involved in designing low-power circuitry, from transistors to logic gates. The book is organized into three broad sections for convenient access. The first examines the history of low-power electronics along with a look at emerging and possible future technologies. It also considers other technologies, such as nanotechnologies and optical chips, that may be useful in designing integrated circuits. The second part explains the techniques used to reduce power consumption at low levels. These include clock gating, leakage reduction, interconnecting and communication on chips, and adiabatic circuits. The final section discusses various CAD tools for designing low-power circuits. This section includes three chapters that demonstrate the tools and low-power design issues at three major companies that produce logic synthesizers. Providing detailed examinations contributed by leading experts, Low-Power CMOS Circuits: Technology, Logic Design, and CAD Tools supplies authoritative information on how to design and model for high performance with low power consumption in modern integrated circuits. It is a must-read for anyone designing modern computers or embedded systems.




Testing and Reliable Design of CMOS Circuits


Book Description

In the last few years CMOS technology has become increas ingly dominant for realizing Very Large Scale Integrated (VLSI) circuits. The popularity of this technology is due to its high den sity and low power requirement. The ability to realize very com plex circuits on a single chip has brought about a revolution in the world of electronics and computers. However, the rapid advance ments in this area pose many new problems in the area of testing. Testing has become a very time-consuming process. In order to ease the burden of testing, many schemes for designing the circuit for improved testability have been presented. These design for testability techniques have begun to catch the attention of chip manufacturers. The trend is towards placing increased emphasis on these techniques. Another byproduct of the increase in the complexity of chips is their higher susceptibility to faults. In order to take care of this problem, we need to build fault-tolerant systems. The area of fault-tolerant computing has steadily gained in importance. Today many universities offer courses in the areas of digital system testing and fault-tolerant computing. Due to the impor tance of CMOS technology, a significant portion of these courses may be devoted to CMOS testing. This book has been written as a reference text for such courses offered at the senior or graduate level. Familiarity with logic design and switching theory is assumed. The book should also prove to be useful to professionals working in the semiconductor industry.







Dual Mode Logic


Book Description

This book presents Dual Mode Logic (DML), a new design paradigm for digital integrated circuits. DML logic gates can operate in two modes, each optimized for a different metric. Its on-the-fly switching between these operational modes at the gate, block and system levels provide maximal E-D optimization flexibility. Each highly detailed chapter has multiple illustrations showing how the DML paradigm seamlessly implements digital circuits that dissipate less energy while simultaneously improving performance and reducing area without a significant compromise in reliability. All the facets of the DML methodology are covered, starting from basic concepts, through single gate optimization, general module optimization, design trade-offs and new ways DML can be integrated into standard design flows using standard EDA tools. DML logic is compatible with numerous applications but is particularly advantageous for ultra-low power, reliable high performance systems, and advanced scaled technologies Written in language accessible to students and design engineers, each topic is oriented toward immediate application by all those interested in an alternative to CMOS logic. Describes a novel, promising alternative to conventional CMOS logic, known as Dual Mode Logic (DML), with which a single gate can be operated selectively in two modes, each optimized for a different metric (e.g., energy consumption, performance, size); Demonstrates several techniques at the architectural level, which can result in high energy savings and improved system performance; Focuses on the tradeoffs between power, area and speed including optimizations at the transistor and gate level, including alternatives to DML basic cells; Illustrates DML efficiency for a variety of VLSI applications.




Multi-voltage CMOS Circuit Design


Book Description

This book presents an in-depth treatment of various power reduction and speed enhancement techniques based on multiple supply and threshold voltages. A detailed discussion of the sources of power consumption in CMOS circuits will be provided whilst focusing primarily on identifying the mechanisms by which sub-threshold and gate oxide leakage currents are generated. The authors present a comprehensive review of state-of-the-art dynamic, static supply and threshold voltage scaling techniques and discuss the pros and cons of supply and threshold voltage scaling techniques.







Designing CMOS Circuits for Low Power


Book Description

This book is the fourth in a series on novel low power design architectures, methods and design practices. It results from of a large European project started in 1997, whose goal is to promote the further development and the faster and wider industrial use of advanced design methods for reducing the power con sumption of electronic systems. Low power design became crucial with the wide spread of portable infor mation and communication terminals, where a small battery has to last for a long period. High performance electronics, in addition, suffers from a per manent increase of the dissipated power per square millimeter of silicon, due to the increasing clock-rates, which causes cooling and reliability problems or otherwise limits the performance. The European Union's Information Technologies Programme 'Esprit' did therefore launch a 'Pilot action for Low Power Design', which eventually grew to 19 R&D projects and one coordination project, with an overall budget of 14 million EURO. It is meanwhile known as European Low Power Initiative for Electronic System Design (ESD-LPD) and will be completed in the year 2002. It involves to develop or demonstrate new design methods for power reduction, while the coordination project takes care that the methods, experiences and results are properly documented and publicised.